In PvE raids, BM for single target, Survival for anything with AoEing and anything that penalises pets.
In PvE 5 mans / challenge modes, Survival.
in PvE soloing, BM.

For PvP, in Arena BM. In BGs, BM or Survival (Entrapment is great, it won't help you kill things but it can really help your whole team with the actual objectives). Remember though that Survival is a DoT spec so it's good when coupled other strong DoT classes.

With currently available gear (even BiS) MM is too far behind in damage to make it's limited utility have any real purpose. Unless you just prefer playing it.

At the moment BM (single) and SV (AOE) are the strongest however, they are getting closer and closer as my gear gets better (Currently 473). SV is becoming stronger for me personally but that could be down to me knowing the spec alot better then BM as I have used it for the last expac.

MM is still lacking however there is a buff coming which will pull it up but I doubt it will get close.

If it doesn't involve AOE or consistent multiple targets throughout the fight, go BM. BM has an undeniable (and raid log proven) advantage over the other two specs. MM is in a pitiful spot right now and the buffs in 5.1 won't bring the spec up too much I'm afraid. The spec needs a flat damage increase on the main abilities (aimed, chimera, and steady).

If we look at Noxxic.com satistic here, that says Beastmaster is the best spec for the hunters again. Is it true or I should stay Survival?

If you actually looked at Noxxic you would also see this:

Please note that these numbers reflect theoretical maximum DPS and not the DPS you are likely to see in-game. Player skill, gear, latency, and many other factors may change these estimates, but they are still useful in evaluating DPS across specs and classes.

MM is not that bad dps wise its, the problem is with all the new things blizz added to the class it made the rotation for marks damn near impossible. Dont look at parses because there aren't enough people playing MM to give you a legit dps number. But if you go to female dwarf or any other sim you will see that MM if played perfect is around the same dps as the other spec. But the key phrase is "played perfect" and that is extremely hard to do. BM and SV are more user friendly a the moment. If you go by sim crafting SV is actually the worse spec on a patchwerk fight with all BIS gear.

Interestingly also, me and my 2 fellow hunter's in our 25man raid always spec Survival for trash mobs even if the upcoming boss is a BM job. The AoE numbers are just hilariously high on big packs.

For Soloing/questing I always feel BM is best, simply because of the amount of damage that the pet can do while you do other things or other quests. i.e. if you have 2 quests one to kill and one to collect: AoE pull to a tanking pet then run around collecting. By the time you get back the mobs are almost dead. You can do that as the other specs too of course, but I tried several methods and BM seems like the most efficient. Also - as BM is a big cooldown spec (Bestial Wrath mainly) it gets heavily favoured by any stop-start situation simply because the cooldowns all come up when you're going between fights/mobs so you get a disproportionate uptime with them. Having said that for straight up non-multitasking AoE questing survival is most liekly better.

BLUF/TLDR: play BM if you wanna roll face. Play Surv if you have skills.

While this is might be true for AoE fights, all simulations and logs point out BM is superior for pure single target fights. This is a fact, not an opinion. However, Survival is easily the more flexible one, with smaller emphasis on pet dmg (good for fights where your pet has to move a lot without being able to attack) and much better AoE. (Exception: Amber-Shaper Un'sok - BM seems to be better, cause your pet can get to the boss faster than you while dodging the tornados, and you can use KC from a great distance.)

EDIT: Not Amber-Shaper Un'sok, but Blade Lord Ta'yak. Thanks for the correction.

While this is might be true for AoE fights, all simulations and logs point out BM is superior for pure single target fights. This is a fact, not an opinion. However, Survival is easily the more flexible one, with smaller emphasis on pet dmg (good for fights where your pet has to move a lot without being able to attack) and much better AoE. (Exception: Amber-Shaper Un'sok - BM seems to be better, cause your pet can get to the boss faster than you while dodging the tornados, and you can use KC from a great distance.)

Wrong boss bro, Blade Lord Ta'yak is the one with tornadoes, Amber-shaper Un'sok has the big orange giant